For many years an iron-nickel-chromium alloy nominally containing 30-35% Ni, 19-23% Cr, 0.15 to 0.6% aluminum, 0.15 to 0.6% titanium, up to 0.75% copper, up to 1% silicon, about 0.1% carbon, iron balance plus impurities, has been used in such applications as heat exchanger tubing, process piping, carburizing fixtures and retorts, furnace components, heating element sheathing, etc. It is known for its resistance to oxidation at elevated temperatures and for a number of other properties, including stable structure, ductility, resistance to carburization, corrosion resistance, etc.